Re: [Bugme-new] [Bug 15494] New: BUG: key ffff88013d4f4c70 not in .data! when loading microcode.ko

[Peter Zijlstra <peterz@infradead.org>]

On Thu, 2010-03-18 at 14:35 -0700, Andrew Morton wrote:
> (switched to email.  Please respond via emailed reply-to-all, not via the
> bugzilla web interface).
> 
> On Tue, 9 Mar 2010 16:28:21 GMT
> bugzilla-daemon@bugzilla.kernel.org wrote:
> 
> > http://bugzilla.kernel.org/show_bug.cgi?id=15494
> 
> Seems to be a post-2.6.33 regression.
> 
> >            Summary: BUG: key ffff88013d4f4c70 not in .data! when loading
> >                     microcode.ko
> >            Product: Drivers
> >            Version: 2.5
> >     Kernel Version: 2.6.34-rc1
> >           Platform: All
> >         OS/Version: Linux
> >               Tree: Mainline
> >             Status: NEW
> >           Severity: normal
> >           Priority: P1
> >          Component: Other
> >         AssignedTo: drivers_other@kernel-bugs.osdl.org
> >         ReportedBy: avillaci@ceibo.fiec.espol.edu.ec
> >         Regression: Yes
> > 
> > 
> > Created an attachment (id=25426)
> >  --> (http://bugzilla.kernel.org/attachment.cgi?id=25426)
> > Full dmesg output for 2.6.34-rc1 on my machine
> > 
> > When loading the module microcode.ko on my 64-bit system, I get the following
> > dump on the kernel log:
> > 
> > [   10.774690] ------------[ cut here ]------------
> > [   10.774726] WARNING: at kernel/lockdep.c:2706 lockdep_init_map+0x114/0x130()
> > [   10.774759] Hardware name:         
> > [   10.774774] Modules linked in: microcode(+) kvm_intel kvm uinput
> > snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq
> > snd_seq_device snd_pcm snd_timer snd i2c_i801 soundcore iTCO_wdt snd_page_alloc
> > iTCO_vendor_support ppdev parport_pc parport pcspkr r8169 mii dm_multipath i915
> > drm_kms_helper drm i2c_algo_bit i2c_core video output [last unloaded:
> > scsi_wait_scan]
> > [   10.775026] Pid: 1939, comm: modprobe Not tainted 2.6.34-rc1 #9
> > [   10.775048] Call Trace:
> > [   10.775063]  [<ffffffff81048006>] warn_slowpath_common+0x76/0xb0
> > [   10.775087]  [<ffffffff8104804f>] warn_slowpath_null+0xf/0x20
> > [   10.775109]  [<ffffffff81073c34>] lockdep_init_map+0x114/0x130
> > [   10.775139]  [<ffffffff8115b3aa>] sysfs_add_file_mode+0x6a/0xc0
> > [   10.775163]  [<ffffffff8115b40c>] sysfs_add_file+0xc/0x10
> > [   10.775185]  [<ffffffff8115d8a1>] sysfs_create_bin_file+0x21/0x30
> > [   10.775209]  [<ffffffff812945bd>] _request_firmware+0x21d/0x4e0
> > [   10.775232]  [<ffffffff8129490e>] request_firmware+0xe/0x10
> > [   10.775256]  [<ffffffffa00f1bc1>] request_microcode_fw+0x61/0xa0 [microcode]
> > [   10.775283]  [<ffffffff8115db01>] ? internal_create_group+0xc1/0x1a0
> > [   10.775309]  [<ffffffffa00f13b8>] microcode_init_cpu+0xb8/0xd0 [microcode]
> > [   10.775336]  [<ffffffffa00f1426>] mc_sysdev_add+0x56/0x70 [microcode]
> > [   10.775361]  [<ffffffff8128a04e>] sysdev_driver_register+0x9e/0x130
> > [   10.775386]  [<ffffffffa0130000>] ? microcode_init+0x0/0x12b [microcode]
> > [   10.775412]  [<ffffffffa01300be>] microcode_init+0xbe/0x12b [microcode]
> > [   10.775438]  [<ffffffff810001d7>] do_one_initcall+0x37/0x190
> > [   10.775462]  [<ffffffff8107fe4b>] sys_init_module+0xdb/0x250
> > [   10.775485]  [<ffffffff81002e6b>] system_call_fastpath+0x16/0x1b
> > [   10.775508] ---[ end trace e0218cb5fc4c0bc8 ]---
> > 
> > This dump did not appear with vanilla 2.6.33.
> > 
> > Steps to reproduce:
> > 1) compile 2.6.34-rc1 with attached configuration
> > 2) run on 64-bit intel machine
> > 3) load microcode.ko or make system configuration load it.
> > 
> > Actual results:
> > kernel dump as shown above
> > 
> > Expected results: 
> > no dump, microcode should load normally
> > 
> 
> Methinks 6992f5334995af474c2b58d010d08bc597f0f2fe ("sysfs: Use one
> lockdep class per sysfs attribute") is implicated.  

You're right, that patch adds a key to struct attribute, and the
firmware stuff seems to dynamically allocate these things in
firmware_priv::bin_attribute::attr.

The allocation seems to happen in fw_register_device().

So yes, that patch is incompatible with the firmware usage, as struct
lock_class_key's are required to be in static storage.